Guitar neck joint routing system

ABSTRACT

A guitar neck joint routing system. The system includes a probe and router assembly comprising a gantry, a probe, and a plurality of routers, and a guitar neck and body nest comprising clamps and vacuum grips for holding a guitar neck and guitar body in place for taking measurements and routing a dovetail joint.

FIELD OF THE INVENTION

The invention relates generally to the field of musical instrumentmanufacture. More particularly, the invention relates to automatedguitar neck joint routing systems, and methods for routing dovetailjoints for joining guitar bodies and guitar necks together.

BACKGROUND OF THE INVENTION

Various publications, including patents, published applications,technical articles and scholarly articles are cited throughout thespecification. Each of these cited publications is incorporated byreference, in its entirety and for all purposes, in this document.

In the assembly of certain types of guitars, including acoustic guitars,the neck of the guitar is fastened to the body of the guitar by way of awooden joint between the bottom of the neck, which is typically referredto as the heel, and the shoulder of the body of the guitar. Forstructural integrity of a joint between an otherwise hollow acousticguitar body and a solid heel, the guitar body typically includes a frontblock (formed from wood) underneath the top surface and at the shoulder.The heel may be secured into this front block.

As one way of fastening the heel into the front block, a specializedjoint may be created, for example, by cutting a mortise in either theheel or the front block, and by fashioning a matching tenon on theopposite portion. For example, the heel typically includes a tenon thatis inserted into a mortise cut into the front block in the guitar body.With the mortise and tenon together, the joint may be secured with glueand with fasteners such as screws and/or bolts.

While such connections are strong, tension on the joint from tightenedguitar strings may weaken the joint over time, and may cause the gluebond to fail, or in the worst case, the joint itself to fail. Even ifthe joint remains structurally sound, the presence of metal implementssuch as screws and bolts within the body may negatively affect soundquality of the instrument, and if these metal implements ever becomeloose, they may rattle and cause undesirable noise to emanate from theinstrument when the instrument is moved, including during a performance.Therefore, there is a need to improve the connection between the neckand the body, with a goal of removing fasteners, particularly metalfasteners. In addition, there is a need to be able to preparehigh-quality, tight connections between the neck and body in a highthroughput manner, particularly with respect to high volume productionof acoustic guitars.

SUMMARY OF THE INVENTION

The invention provides guitar neck-joint routing systems. In someaspects, a guitar neck-joint routing system comprises a probe and routerassembly comprising a gantry, a probe, and a plurality of routers; aguitar neck and body nest comprising a guitar body clamp, an upperguitar neck clamp, a lower guitar neck clamp, a face probe, and nestactuator; and, a programmable logic controller comprising a humanmachine interface, a programmable processor, and memory.

A gantry may comprise an upper track and a lower track, a hoist track, agantry actuator for moving the probe and router assembly laterally alongthe upper track and lower track, a hoist, and a hoist actuator formoving the probe and router assembly vertically along the hoist track.In some aspects, the probe may be mounted on a probe shuttle, which maybe mounted on a probe track. The probe may comprise a sensor tip formeasuring the geometry and surface features of a guitar neck and aguitar body, a probe processor in communication with the sensor tip andthe programmable logic controller, and a probe plane actuator for movingthe probe about a surface on the guitar neck and/or a surface on theguitar body. In some aspects, each router may be mounted on a routershuttle that is mounted on a router track, and each router preferablycomprises a cutting tool and a router processor in communication withthe programmable logic controller.

The body clamp may comprise a body platen, an upper guitar neck platen,an upper guitar neck guide pin, a lower guitar neck platen, a lowerguitar neck guide pin, a plurality of vacuum grips each comprising avacuum source, and a guitar neck joint locator comprising a plurality ofneck joint locator pins. The upper guitar neck clamp may be a precisionpneumatic cylinder, and may comprise an upper neck clamp slide slidablyconnected to an upper neck bracket. The lower guitar neck clamp may be aprecision pneumatic cylinder, and may comprise a lower neck clamp slideslidably connected to a lower neck bracket.

The face probe may comprise a face probe sensor tip for measuring thegeometry and surface features of the front face of the guitar body, anda face probe processor in communication with the face probe sensor tipand the programmable logic controller. The nest actuator is preferablycapable of moving or pivoting the guitar neck and body nest to an anglecalculated by the programmable logic controller for cutting afingerboard pocket on the front face of the guitar body, cutting a heelpocket into the shoulder of a guitar body, and cutting a dovetail intothe shoulder of a guitar body.

The programmable logic controller may comprise executable code forcausing a programmable processor to cause the probe to measure thegeometry and surface features of a guitar neck and a guitar body,executable code for causing a programmable processor to cause the faceprobe to measure the geometry and surface features of the front face ofthe guitar body, and executable code for causing a programmableprocessor to cause the plurality of routers to cut portions of theguitar body to create a dovetail joint according to the measurements ofthe geometry and surface features of the guitar neck and guitar body.The programmable processor may comprise a computer. The human machineinterface may comprise a graphical user interface.

The invention also provides methods for routing a dovetail joint on aguitar shoulder. The methods may comprise one or more of (and in anyorder) determining if the bridge locus on the front face of a guitarbody is flat, concave, or convex; determining if the neck angle betweenthe heel and the finger board of a guitar neck deviates from a thresholdangle; determining the thickness of the lower portion of the fingerboard of the guitar neck; determining whether the angle of a dovetailjoint on the heel is perpendicular or non-perpendicular to the fingerboard of the guitar neck; determining the geometry of the finger boardand the heel; determining the top drop angle on the guitar body; anddetermining the horizontal position of the shoulder of the guitar body.Any one, a plurality, or all of the determining steps may be carried outusing a processor programmed to carry out the determining step. Themethods may comprise cutting a finger board pocket on the front face ofthe guitar body taking into account the geometry of the finger board;cutting a heel pocket on the shoulder of the guitar body taking intoaccount the shape of the bridge portion, the neck angle, the top dropangle, the presence of low spots on the shoulder, the finger boardthickness, and the geometry of the heel; and, cutting a dovetail jointin the shoulder of the guitar body taking into account the angle of thedovetail joint on the heel.

The methods may comprise cutting the heel pocket on the shoulder forwardangle if the bridge locus is concave, or cutting the heel pocket at abackward angle if the bridge locus is convex. The methods may comprisecutting the heel pocket on the shoulder at a forward angle if the neckangle is greater than the threshold angle, or cutting the heel pocket onthe shoulder at a backward angle if the neck angle is less than thethreshold angle. The methods may comprise cutting the heel pocket on theshoulder at a forward angle if the finger board thickness is greaterthan a nominal thickness, or cutting the heel pocket on the shoulder ata backward angle if the finger board thickness is less than a nominalthickness. The methods may comprise cutting the opposite side of thedovetail angle at ½ the distance of non-perpendicularity if the angle ofthe dovetail joint on the heel is not perpendicular to the finger boardof the guitar neck.

In some aspects, the methods comprise cutting the heel pocket on theshoulder at a backward angle if the top drop angle is less than anominal angle, or cutting the heel pocket on the shoulder at a forwardangle if the top drop angle is greater than the nominal angle. Themethods may further comprise cutting the shoulder of the guitar bodyequal to the depth of the lowest low spot determined on the shoulder.

The invention also provides dovetail joints, including dovetail jointsproduced according to the methods. In some aspects, a dovetail jointcomprises a female portion comprising an angle of about 8 degrees and ataper of about 0.0265 inches (0.673 mm) to about 0.0295 inches (0.749mm) per side. In some aspects, a dovetail joint comprises a male portioncomprising an angle of about 10 degrees and a taper of about 0.0265inches (0.673 mm) to about 0.0295 inches (0.749 mm) per side.

A guitar body may comprise the dovetail joint, or a female portionthereof. A female portion of a dovetail joint in a guitar body maycomprise an angle of about 8 degrees and a taper of about 0.0265 inches(0.673 mm) to about 0.0295 inches (0.749 mm) per side. A guitar maycomprise a dovetail joint, or a female portion thereof. A female portionof a dovetail joint in a guitar may comprise an angle of about 8 degreesand a taper of about 0.0265 inches (0.673 mm) to about 0.0295 inches(0.749 mm) per side. The guitar body may be an acoustic guitar body. Theguitar may be an acoustic guitar. The dovetail joint is preferably inwood, and preferably does not include any metal fasteners securing themale portion and female portion together.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is best understood from the following detailed descriptionwhen read in connection with the accompanying drawings. It is emphasizedthat, according to common practice, the various features of the drawingsare not to scale. On the contrary, the dimensions of the variousfeatures are arbitrarily expanded or reduced for clarity. Included inthe drawings are the following figures:

FIG. 1 shows a guitar neck joint routing system enclosed within a frame;

FIG. 2 shows a front perspective of a probe and router assembly;

FIG. 3 shows a side perspective of the probe and router assembly;

FIG. 4 shows a rear perspective of the probe and router assembly;

FIG. 5 shows a rear perspective of a guitar neck and body nest;

FIG. 6 shows a bottom perspective of a guitar body clamp;

FIG. 7 shows a rear perspective of a guitar neck and body nest with theface probe cover removed;

FIG. 8 shows a bottom perspective of a guitar neck and body nest;

FIG. 9 shows a front perspective of a guitar neck and body nest;

FIG. 10 shows a rear perspective of a guitar neck and body nest;

FIG. 11 shows a top perspective of a guitar neck and body nest;

FIG. 12 shows a side perspective of a guitar neck joint routing system;

FIG. 13 shows a top perspective of a guitar neck joint routing system;

FIG. 14 shows a front perspective of a guitar neck joint routing system;

FIG. 15 a shows a graphical illustration of measurements taken by aguitar and neck routing system;

FIG. 15 b shows a graphical illustration of additional measurementstaken by the guitar and neck routing system;

FIG. 15 c shows an illustration of a measurement of the male dovetailangle of perpendicularity or non-perpendicularity and is a cross-sectiontaken along the line 15 c-15 c of FIG. 15 b;

FIG. 15 d shows an illustration of additional measurements taken by theguitar and neck routing system;

FIG. 15 e shows an illustration of additional measurements taken by theguitar and neck routing system;

FIG. 16 shows a logic flow diagram for determining the geometry andsurface features of a guitar neck and a guitar body;

FIG. 17 is a continuation of FIG. 16, and shows a logic flow diagram forgeometry and surface features of a guitar neck and a guitar body;

FIG. 18 shows a logic flow diagram for determining the features of thefront face of a guitar body in the area where a bridge will be mounted;

FIG. 19 shows a logic flow diagram for determining the neck angle on aguitar neck;

FIG. 20 shows a logic flow diagram for determining the thickness of afinger board;

FIG. 21 shows a logic flow diagram for determining whether a dovetailangle is perpendicular or non-perpendicular;

FIG. 22 shows a logic flow diagram for determining the deviation from atop drop standard;

FIG. 23 shows a logic flow diagram for determining low spots on shoulderbody joint surface;

FIG. 24 shows a logic flow diagram for cutting a guitar neck and guitarbody;

FIG. 25 a shows a perspective of a dovetail joint angle;

FIG. 25 b shows a male portion of a dovetail joint and a female portionof a dovetail joint; and,

FIG. 25 c shows a tapered dovetail joint in which the male portion andfemale portion are brought together with a tight fit.

DETAILED DESCRIPTION OF THE INVENTION

Various terms relating to aspects of the invention are used throughoutthe specification and claims. Such terms are to be given their ordinarymeaning in the art, unless otherwise indicated. Other specificallydefined terms are to be construed in a manner consistent with thedefinition provided in this document.

As used throughout, the singular forms “a,” “an,” and “the” includeplural referents unless expressly stated otherwise.

The invention features devices, systems, and methods for routing adovetail neck joint for joining a guitar body and guitar neck together.The devices, systems, and methods may find use, for example, in guitarmanufacture. A foundational feature is a tapered dovetail joint, and anautomated process for producing the joint.

The components of the system can be fabricated from any suitablematerial or combination of materials. Materials include metal, plastic,polymers, glass, rubber, and composites.

Referring now to the drawings, in which like reference numbers refer tolike elements throughout the various figures that comprise the drawings,FIG. 1 shows one non-limiting embodiment of a guitar neck joint routingsystem 10, including a frame 20, a programmable logic controller (PLC)30 with a graphical user interface 32, a probe and router assembly 100,and a guitar neck and body nest 400. The PLC 30 is enclosed within anenclosure, and may comprise software for controlling the system,movement of its various components, calculations involving mathematicalequations, and manipulation of the graphical user interface 32.

The probe and router assembly 100 includes components that measureportions of a guitar neck 502 and a guitar body 510, and cut a dovetailjoint 508, 518 between them to ensure a proper fit of neck 502 and thebody 510 during assembly of a guitar. In some preferred embodiments, theprobe and router assembly 100 components cut a female portion 518 of adovetail joint 508, 518. FIG. 2 shows one embodiment of the probe androuter assembly 100 from a front perspective. As shown in FIG. 2, theassembly 100 includes basic structural features, including a gantry 200,an upper gantry track 208, a lower gantry track 212, a router platen104, and a probe platen 106.

The router platen 104 supports a plurality of routers. As shown in FIG.2, the assembly 100 may comprise three routers, including a first router120, a second router 130, and a third router 140. Each router 120, 130,and 140 cuts one or more portions of the guitar body 510 to generate afemale portion 518 of the dovetail joint 508, 518 for joining the guitarneck 502 and guitar body 510 together when assembling a guitar.

Each of the first 120, second 130, and third 140 routers comprisesubstantially the same components. For example, the first router 120includes a first motor housing 122 that encloses a first motor (notshown), a first chuck 124 that holds a first cutting tool 126, a firstprocessor 128, and a first input (not shown) operably connected to thefirst processor 128. The second router 130 includes a second motorhousing 132 that encloses a second motor (not shown), a second chuck 134that holds a second cutting tool 136, a second processor 138, and asecond input (not shown) operably connected to the second processor 138.The third router 140 includes a third motor housing 142 that encloses athird motor (not shown), a third chuck 144 that holds a third cuttingtool 146, a third processor 148, and a third input (not shown) operablyconnected to the third processor 148. The first motor, the second motor,and the third motor may each independently comprise an air-driven motor.

The first 126, second 136, and third 146 cutting tools may comprise arouter bit 126, 136, and 146 of any suitable shape or size. For example,a router bit 126, 136, and 146 may comprise a rabbet bit, a dovetailbit, a surface bit, a straight bit, a mortise bit, a chamfer bit, anabrasive bit, or other suitable router bit, the shapes of which arewell-known in the art. The first 126, second 136, and third 146 cuttingtools may comprise a blade, or may comprise a laser cutter.

The first 128, second 138, and third 148 processors may receive a signalthrough the first, second, and third inputs, respectively. The signalmay originate, for example, from the PLC 30. The signal causes the first128, second 138, and third 148 processors to cause activation of thefirst 120, second 130, and third 140 routers, respectively, and to causeeach of the first 120, second 130, and third 140 routers to cut a guitarneck 502 and a guitar body 510 according to specifications determined bythe PLC 30 of the system 10. Cutting of the guitar body 510 ispreferably automated. If the system 10 makes any cuts on the guitar neck502, such cuts are also preferably automated.

The first router 120 is preferably mounted on a first shuttle 152, whichis preferably mounted on a first router track 150. In an alternativeembodiment, the first router 120 is mounted directly on the first routertrack 150. Whether mounted on the first shuttle 152 or the first track150, the first router 120 may move laterally along a z-plane Forexample, the first shuttle 152, or the first router 120 itself, may movealong the first router track 150, which is positioned in a z-planerelative to an x-plane and a y-plane established by the geometry of thegantry 200. Movement of the first shuttle 152 or the first router 120along the first track 150 is controlled by a first router actuator (notshown). The first router actuator causes the first shuttle 152 or thefirst router 120 to move back and forth along the first router track150. The first router actuator may comprise a linear actuator, and maycomprise a cylinder-piston assembly, a hydraulic actuator, a camactuator, a pneumatic actuator, a wheel and axel, a winch, a rack andpinion, or a screw.

The mounting of the first router 120 to the first shuttle 152 or to thefirst router track 150, may comprise a first hinge (not shown). Thus,the first router 120 may also flip from its position in a horizontalplane to a position in a vertical plane such that the first cutting tool126 may point downward, and reverse back to the horizontal plane. Forexample, FIG. 2 shows the first router 120 positioned in a horizontalplane, substantially parallel with the z-plane of the first router track150. FIG. 2 shows the third router 140 positioned in a vertical plane,substantially perpendicular with the z-plane of both the first routertrack 150 and a third router track 170. FIG. 2 thus illustrates twopossible positions that each router 120, 130, and 140 may assume—aposition in a horizontal plane, or a position in a vertical plane. Thelatter position is preferably the position the router 120, 130, or 140assumes when it is engaged to cut the guitar neck 502 and/or guitar body510. The first hinge allows the first router 120 to move between thehorizontal position and the vertical position as shown. A first hingeactuator (not shown) moves the first router 120 between the horizontaland vertical positions via the first hinge. The first hinge actuator maycomprise a linear actuator, and may comprise a cylinder-piston assembly,a hydraulic actuator, a cam actuator, a pneumatic actuator, a wheel andaxel, a winch, a rack and pinion, or a screw.

The second router 130 is preferably mounted on a second shuttle 162,which is preferably mounted on a second router track 160. In analternative embodiment, the second router 130 is mounted directly on thesecond router track 160. Whether mounted on the second shuttle 162 orthe second track 160, the second router 130 may move laterally along az-plane. For example, the second shuttle 162, or the second router 130itself, may move along the second router track 160, which is positionedin a z-plane relative to the x-plane and y-plane established by thegeometry of the gantry 200. Movement of the second shuttle 162 or thesecond router 130 along the second track 160 is controlled by a secondrouter actuator (not shown). The second router actuator causes thesecond shuttle 162 or the second router 130 to move back and forth alongthe second router track 160. The second router actuator may comprise alinear actuator, and may comprise a cylinder-piston assembly, ahydraulic actuator, a cam actuator, a pneumatic actuator, a wheel andaxel, a winch, a rack and pinion, or a screw.

The mounting of the second router 130 to the second shuttle 162 or tothe second router track 160 may comprise a second hinge (not shown).Thus, the second router 130 may also flip from its position in ahorizontal plane to a position in a vertical plane such that the secondcutting tool 136 may point downward, and vice versa. For example, FIG. 2shows the second router 130 positioned in a horizontal plane,substantially parallel with the z-plane of the second router track 160.FIG. 2 shows the third router 140 positioned in a vertical plane,substantially perpendicular with the z-plane of both the second routertrack 160 and the third router track 170. The second hinge allows thesecond router 130 to move between the horizontal position and thevertical position as shown in FIG. 2. A second hinge actuator (notshown) moves the second router 130 between the horizontal and verticalpositions via the second hinge. The second hinge actuator may comprise alinear actuator, and may comprise a cylinder-piston assembly, ahydraulic actuator, a cam actuator, a pneumatic actuator, a wheel andaxel, a winch, a rack and pinion, or a screw.

The third router 140 is preferably mounted on a third shuttle 172, whichis preferably mounted on a third router track 170. In an alternativeembodiment, the third router 140 is mounted directly on the third routertrack 170. Whether mounted on the third shuttle 172 or the third track170, the third router 140 may move laterally along a z-plane. Forexample, the third shuttle 172, or the third router 140 itself, may movealong the third router track 170, which is positioned in a z-planerelative to the x-plane and y-plane established by the geometry of thegantry 200. Movement of the third shuttle 172 or the third router 140along the third track 170 is controlled by a third router actuator 174.The third router actuator 174 causes the third shuttle 172 or the thirdrouter 140 to move back and forth along the third router track 170. Thethird router actuator 174 may comprise a linear actuator, and maycomprise a cylinder-piston assembly, a hydraulic actuator, a camactuator, a pneumatic actuator, a wheel and axel, a winch, a rack andpinion, or a screw.

The mounting of the third router 140 to the third shuttle 172 or thethird router track 170 may comprise a third hinge 176. Thus, the thirdrouter 140 may also flip from its position in a horizontal plane to aposition in a vertical plane such that the third cutting tool 146 maypoint downward, and vice versa. For example, FIG. 2 shows the thirdrouter 140 positioned in a vertical plane, substantially perpendicularwith the z-plane of the third router track 170. The third hinge 176allows the third router 140 to move between the horizontal position andthe vertical position as shown in FIG. 2. A third hinge actuator 178moves the third router 140 between the horizontal and vertical positionsvia the third hinge 176. The third hinge actuator 178 may comprise alinear actuator, and may comprise a cylinder-piston assembly, ahydraulic actuator, a cam actuator, a pneumatic actuator, a wheel andaxel, a winch, a rack and pinion, or a screw. FIG. 3 shows the thirdrouter 140 in the vertical position, and shows the third hinge 176 andthird hinge actuator 178 on the third router 140.

The probe platen 106 supports at least one probe 180. As shown in FIG. 2and FIG. 3, the assembly 100 may comprise a single probe 180. The probe180 measures portions of the guitar neck 502 and guitar body 510 andcommunicates its measurements to the PLC 30 to allow the PLC 30 todetermine the dimensions for cutting at least the female portion 518 ofthe dovetail joint 508, 518 for joining the neck 502 and body 510together when assembling a guitar.

The probe 180 comprises a probe processor housing 182, which contains aprobe processor 184 to which is operably connected a probe processorinput (not show) and a probe processor output (not shown), and comprisesa sensor tip 186. The sensor tip 186 takes measurements, includinglength, width, height, angles, distortions, and other geometric andsurface features of the guitar neck 502, the guitar heel 504 portion ofthe neck 502, the guitar finger board 506 portion of the neck 502, themale dovetail joint 508 portion of the neck 502, the guitar body 510,the front face 512 of the guitar body 510, and/or the shoulder 514 ofthe guitar body 510, and the female dovetail joint 518 portion of theguitar body 510. The sensor tip 186 is operably connected to the probeprocessor input and sends a signal concerning information about themeasurements to the probe processor 184 via the input, and the probeprocessor 184 relays the signal to the PLC 30 via the probe processoroutput. The sensor tip 186 may comprise one or more lasers, wheels,balls, or other suitable sensors, including sensors that takemeasurements based on machine vision.

The probe 180 is preferably mounted on a probe shuttle 192, which ispreferably mounted on a probe track 190. In an alternative embodiment,the probe 180 is mounted directly on the probe track 190. Whethermounted on a probe shuttle 192 or a probe track 190, the probe 180 maymove laterally along a z-plane. For example, the probe shuttle 192, orthe probe 180 itself, may move along the probe track 190, which ispositioned in a z-plane relative to the x-plane and y-plane establishedby the geometry of the gantry 200. Movement of the probe shuttle 192 orthe probe 180 along the probe track 190 is controlled by a probeactuator 194. The probe actuator 194 causes the probe shuttle 192 or theprobe 180 to move back and forth along the probe track 190. The probeactuator 194 may comprise a linear actuator, and may comprise acylinder-piston assembly, a hydraulic actuator, a cam actuator, apneumatic actuator, a wheel and axel, a winch, a rack and pinion, or ascrew.

The mounting of the probe 180 to the probe shuttle 192 may comprise aprobe hinge 196, and/or a pivot 197. Thus, the probe 180 may move upwardand downward in a vertical plane, and may also move laterally in ahorizontal plane. Such movement of the probe 180, coupled with theforward and backward movement along a z-plane, moves the sensor tip 186along the surfaces of the wood of the guitar neck 502 and the guitarbody 510 to take the necessary measurements. The probe hinge 196 and/orthe pivot 197 allow the probe 180 to move vertically and laterally, andall other possible directions. A probe plane actuator 198 moves theprobe 180 vertically and laterally via the probe hinge 196 and/or pivot197. The probe plane actuator 198 may comprise a linear actuator, andmay comprise a cylinder-piston assembly, a hydraulic actuator, a camactuator, a pneumatic actuator, a wheel and axel, a winch, a rack andpinion, or a screw.

The gantry 200 provides a basic structural framework to which the routerplaten 104 and the probe platen 106 may be mounted and moved. As shownin FIGS. 2-4, the gantry 200 includes an upper dolly 210 that engagesthe upper gantry track 208 and a lower dolly 214 that engages the lowergantry track 212. The upper dolly 210 and the lower dolly 214 allow thegantry 200 to move laterally along the upper gantry track 208 and thelower gantry track 212 in an x-plane (FIG. 4). Such movement along theupper track 208 and lower track 212 may be effectuated for example, by agantry actuator 216. The gantry actuator 216 may comprise a linearactuator, and may comprise a cylinder-piston assembly, a hydraulicactuator, a cam actuator, a pneumatic actuator, a wheel and axel, awinch, a rack and pinion, or a screw. Lateral movement about the x-planemay allow the probe and router assembly 100 to measure and cut a set ofa guitar neck 502 and a guitar body 510 on one half of the nest 400 a,while an operator loads a new set of a guitar neck 502 and guitar body510 into the other half of the nest 400 b (See FIG. 13 and FIG. 14).

The gantry 200 comprises a gantry frame 201, and comprises a hoist 202to which the probe and router assembly 100 is operably connected. Thehoist 202 moves the probe and router assembly 100 vertically in ay-plane (along the vertical axis), via a hoist track 204. Movement ofthe hoist 202 along the hoist track 204 may be effectuated, for example,by a hoist actuator 206. The hoist actuator 206 may comprise a linearactuator, and may comprise a cylinder-piston assembly, a hydraulicactuator, a cam actuator, a pneumatic actuator, a wheel and axel, awinch, a rack and pinion, or a screw. Different types of guitar necks502 and guitar bodies 510, including their different shapes,configuration, and height, may necessitate that the height of the probeand router assembly 100 be adjusted relative to the wooden components tobe measured and cut, and this height adjustment of the probe and routerassembly 100 may be achieved via vertical movement along the hoist track204.

To hold a guitar body 510 and a guitar neck 502 in place for routing thedovetail joint 508, 518, the system 10 includes a guitar neck and bodynest 400. Various perspectives of the nest 400 are shown on FIGS. 5-11.As shown in FIG. 5, the guitar neck and body nest 400 comprises a bodyclamp 480, on which additional components are present. These componentsinclude an upper neck platen 430 and a lower neck platen 431 onto whicha guitar neck 502 to be measured and routed may be placed. To assistproper positioning of the guitar neck 502 on the upper 430 and lower 431neck platens, the body clamp 480 includes an upper neck guide pin 432and a lower neck guide pin 434, which may be moved or adjusted to ensurethe guitar neck 502 is in the proper orientation before measurements ofthe guitar heel 504 portion of the neck 502, the guitar finger board 506portion of the neck 502, and the male dovetail joint 508 are taken. Theupper neck guide pin 432 and the lower neck guide pin 434 may comprise apneumatic gripper, including a precision pneumatic parallel gripperassembly.

To further assist proper positioning of the guitar neck 502, the bodyclamp 480 includes an upper neck clamp 438 and a lower neck clamp 440.Each of the upper 438 and lower 440 neck clamps may be adjusted alongthe y-plane to help hold the guitar neck 502 firmly in place duringmeasurement and cutting.

The upper neck clamp 438 may be mounted on an upper neck clamp slide439, which may be manually adjusted, for example, by a user pushing orpulling the upper neck slide 439 about the y-plane, and optionallylocking the upper neck clamp 438 in place when the desired position isachieved. In some alternative aspects, the movement of the upper neckclamp 438 about the slide 439 may be effectuated by actuation of anupper pneumatic valve 445. Movement of the upper pneumatic valve 445 maybe effectuated by an upper pneumatic valve actuator 444, which mayengage and disengage the upper neck clamp 438 which travels about theupper neck slide 439. Movement of the upper neck clamp 438 may stop whenthe clamp 438 contacts the surface of the guitar neck 502. The upperneck clamp slide 439 is slidably connected to an upper neck bracket 437,which is affixed to the body clamp 480. The upper neck clamp 438 may bea precision pneumatic cylinder, and air pressure may control theclamping force.

The lower neck clamp 440 may be mounted on a lower neck clamp slide 441,which may be manually adjusted, for example, by a user pushing orpulling the lower neck slide 441 about the y-plane, and optionallylocking the lower neck clamp 440 in place when the desired position isachieved. In some alternative aspects, the movement of the lower neckclamp 440 about the slide 441 may be effectuated by actuation of a lowerpneumatic valve 447. Movement of the lower pneumatic valve 447 may beeffectuated by a lower pneumatic valve actuator 446, which may engageand disengage the lower neck clamp 440 which travels about the lowerneck slide 441. Movement of the lower neck clamp 440 may stop when theclamp 440 contacts the surface of the guitar neck 502. The lower neckslide 441 is slidably connected to a lower neck bracket 443, which isaffixed to the body clamp 480. The lower neck clamp 440 may be aprecision pneumatic cylinder, and air pressure may control the clampingforce.

A guitar body 510 may be held in place within the neck and body nest 400between the body clamp 480 and a body platen 470. On the lower surface481 of the body clamp 480, are a plurality of vacuum grips 482 a-f. FIG.6 shows a non-limiting embodiment of the lower surface 481, and showssix vacuum grips 482 a-f. A vacuum is provided through a vacuum source484 as shown in FIG. 7, which illustrates six vacuum sources 484 a-f.The vacuum flows through the vacuum grips 482 a-f, and secures theguitar body 510 in place during measurement and cutting of the body 510.

Vacuum sources 484 a-f are on the body clamp 480, and are housed withina face probe housing 450, as shown in FIG. 5. The vacuum may becontrolled by the user, for example, by adjusting a T-handle 452 duringoperation of the system 10. Alternatively, the vacuum may be controlledby the PLC 30.

As shown in FIG. 7, the face probe housing 450 houses a face probe 454.The face probe 454 measures the front face 512 of the guitar body 510,about the area where a bridge will be mounted, to determine the bridgeheight that will be required for mounting the bridge onto the front face512 of the body 510 during the latter stages of the assembly of aguitar. The bridge height and proper angle of the mounting of the guitarneck 502 onto the body 510 preferably are taken into account to ensureproper positioning of guitar strings.

The face probe 454 comprises a face probe sensor tip 455 and a faceprobe processor 458 to which is operably connected a face probe input457 and a face probe output 459. The face probe sensor tip 455 takesmeasurements, including length, width, height, angles, distortions, andother geometric and surface features of the front face 512 of the guitarbody 510. The sensor tip 455 is operably connected to the face probeinput 457 and sends a signal concerning information about themeasurements to the face probe processor 458 via the input 457, and theface probe processor 458 relays the signal to the PLC 30 via the faceprobe output 459.

The face probe 454 may access the front surface 512 via a face probebore 486 that passes through the body clamp 480 (FIG. 6). The face probe454 may extend through the bore 486, and pass through the bottom surface481, and onto the front face 512. Movement of the face probe 454 may beeffectuated, for example, with a face probe actuator (not shown). Themovement may be about a y-plane.

To assist in the proper positioning of the guitar body 510 within thenest 400, the body clamp 480 includes a neck joint locator 460 (FIG. 5and FIG. 7). The neck joint locator 460 includes a plurality of neckjoint locator pins 462. FIG. 5 shows a non-limiting embodiment with oneneck joint locator pin 462. The neck joint locator pin 462 matches upwith, and can be inserted into neck joint locator pin hole 516 locatednear the top of the front face 512 of the guitar body 510 (FIG. 5). Theneck joint locator 460 may be mounted on a joint locator hinge 464,which permits the neck joint locator 460 to be raised and lowered inplace, for example, between an open position and closed position. Whenlowered into place, in the closed position, the neck joint locator pin462 is inserted into the neck joint locator pin hole 516. In someaspects, the body clamp 480 includes a bottom locator pin 466 forengaging a bottom pin hole 522 on the bottom of the guitar body 510.

During initial manufacture of the guitar body 510, the top is angledslightly inward, toward the bottom surface 520 of the body 510. Thisangle, referred to as a top drop angle, is taken into account andmeasured by the probe 180. During routing of the guitar body 510 toprepare the female dovetail joint 518, the guitar body 510 may need tobe positioned within the nest 400 to compensate for the top drop angleand ensure proper geometry when the guitar neck 502 and body 510 areassembled into a guitar. To adjust the angle of the guitar body 510being held in place between the body platen 470 and body clamp 480, thenest 400 includes a bottom clamp 472 (FIG. 7).

The bottom clamp 472 contacts the bottom surface 520 of the guitar body510, and may push the body 510 upward in the direction of the bottomsurface 481 of the body clamp 480, for example, to help secure theguitar body 510 firmly in place. Movement of the bottom clamp 472 may beeffectuated, for example, by a bottom clamp actuator 474. The bottomclamp actuator 474 may comprise a linear actuator, and may comprise acylinder-piston assembly, a hydraulic actuator, a cam actuator, apneumatic actuator, a wheel and axel, a winch, a rack and pinion, or ascrew. FIG. 8 shows a bottom perspective of the nest 400, and shows anembodiment of the bottom clamp 472 operably connected to the bottomclamp actuator 474. The bottom clamp actuator 474 may be controlledmanually, for example, by a user pressing a foot pedal 476.Alternatively, the bottom clamp actuator 474 may be controlled by thePLC 30.

The nest 400 preferably also comprises a nest actuator 478, which movesand/or pivots the nest 400 in various angles about the x-axis. Thus, forexample, the nest actuator 478 may move the nest 400 and with it, theguitar body 510 secured within the nest 400. Movement of the nest 400 inthis manner allows tilting of the guitar body 510 at a desired angle,for example, during measurement or cutting of the guitar body 510.Movement of the nest actuator 478 is preferably controlled by the PLC30. In some aspects, movement may be assisted by a nest hinge 479 (FIG.7).

FIGS. 9, 10, and 11 show additional perspectives of the neck and bodynest 400. FIG. 9 shows a front perspective of the nest 400, andillustrates the guitar body 510 secured between the body platen 470 andthe body clamp 480. The female portion 518 of the dovetail joint 508,518 on the shoulder 514 of the guitar body 510 is shown. The maleportion 508 of the dovetail joint 508, 518 on the bottom of the guitarneck 502 and neck heel 504 is shown. FIG. 10 shows a rear perspective ofthe nest 400, and illustrates the guitar body 510 secured between thebody platen 470 and the body clamp 480.

FIG. 11 shows a top perspective of the neck and body nest 400, and showsthe positioning of the guitar body 510 and the guitar neck 502 withinthe body clamp 480 and upper 438 and lower 440 neck clamps. The lowerportion of the guitar fingerboard 506 is shown, and the male portion 508of the dovetail joint 508, 518 is shown on the neck heel 504 of the neck502, and the female portion 518 of the dovetail joint 508, 518 is shownon the guitar body 510.

FIGS. 12, 13, and 14 show positioning of the neck and body nest 400proximate to the probe and router assembly 100. For example, FIG. 12shows a side view of the nest 400 containing a guitar body 510 and aguitar neck 502, and of the assembly 100, including the probe 180 andthe third router 140 in the cutting position.

The neck and body nest 400 may comprise two mirror image portions. FIG.13 and FIG. 14 show one such embodiment with a guitar body 510 a and 510b held in place between a body clamp 480 a and 480 b and body platen 470a and 170 b, and a guitar neck 502 a and 502 b held in place between theupper neck platen (not labeled) and the lower neck platen (not labeled)and the upper neck clamp (not labeled) and lower neck clamp (notlabeled) in each portion. Having two mirror image portions of the neckand body nest 400 a and 400 b allows a user to process up to two guitarbodies 510 a and 510 b and two guitar necks 502 a and 502 b at a giventime. For example, the user may position one set of a guitar body 510 band guitar neck 502 b, while the probe and router assembly 100 measuresand routs another set of a guitar body 510 a and guitar neck 502 a.

Operation of the system 10 is preferably controlled using the PLC 30. Insome aspects, the PLC 30 is programmed to control the measurement andcutting of portions of the guitar neck 502 and the guitar body 510 tocreate a male portion 508 of a dovetail joint 508, 518 on the neck 502and a female portion 518 of a dovetail joint 508, 518 on the body 510.The PLC 30 preferably comprises a human machine interface 32 to enable ahuman being to operate the system 10, and a programmable logiccontroller processor (not shown). The PLC processor comprises at leastone programmable logic controller input (not shown) and at least oneprogrammable logic controller output (not shown) for sending andreceiving signals, respectively, to and from other components of thesystem 10. The PLC processor preferably comprises a memory.

The PLC 30 may comprise executable code for causing a programmableprocessor to cause the probe 180 to measure portions of the guitar neck502, including the neck heel 504, the finger board 506 and the rough-cutmale portion 508 of the dovetail joint 508, 518, and to measure portionsof the guitar body 510, including the front surface 512, the shoulder514, and the female portion 518 of the dovetail joint 508, 518. The PLC30 may comprise executable code for causing a programmable processor tocause the face probe 454 to measure portions of the front face 512 ofthe guitar body 510. The PLC 30 may comprise executable code for causinga programmable processor to cause the nest actuator 478 to move and/orpivot the nest 400 among various angles about the x axis for adjustingthe angle of the guitar body 510 during cutting. The PLC 30 may compriseexecutable code for causing a programmable processor to calculateaspects of the geometric and surface features of the neck 502 and body510, including whether the front face 512 is flat, concave, or convex,neck angle deviations from a threshold angle (e.g., about 90 degrees,including about 89.37 degrees), finger board 506 thickness, angle ofperpendicularity or angle of non-perpendicularity of the male portion508 of the dovetail joint 508, 518 to the finger board 506, thedimensions of the finger board 506 and heel 504, the top drop angle, andhorizontal position of the shoulder, among others. The PLC 30 maycomprise executable code for causing a programmable processor to causethe first router 120, the second router 130, and the third router 140 tocut/rout portions of the front face 512, and shoulder 514 of the guitarbody 510 in order to create a finely-cut female portion 518 of thedovetail joint 508, 518 according to the unique geometry, shapes,dimensions, angles, imperfections, and other surface features measuredfrom a neck 502 and body 510 set. The PLC 30 may comprise executablecode for causing a programmable processor to cause the first router 120,the second router 130, and the third router 140 to cut/rout portions ofthe guitar neck 502 in order to create a finely-cut male portion 508 ofa dovetail joint 508, 518 according to the unique geometry, shapes,dimensions, angles, imperfections, and other surface features measuredfrom a neck 502 and body 510 set. The fine cuts permit the neck 502 andbody 510 to be joined together by matching the finely cut male portion508 and female portion 518 of the dovetail joint 508, 518 duringassembly of a guitar.

The executable code may cause a programmable processor to carry out anoperational logic used in operation of the system 10 that enablesmeasurement of the neck 502, body 510, and front surface 512,calculation of dimensions needed for the male portion 508 and/or femaleportion 518 of the dovetail joint 508, 518, and positioning and movementof the nest 400 (and with it, the body 510 held in place in the nest400) and of each of the first router 120, second router 130, and thirdrouter 140 for making cuts in the wood. FIGS. 15-24 show onenon-limiting embodiment of a logic that can be used to create executablecode and/or used in the operation of the system 10. FIG. 15 a throughFIG. 15 e illustrate measurements taken on each of the neck 502 and body510 according to the operational logic.

During operation of the system 10, a user may position a guitar neck 502onto the upper neck platen 430 and lower neck platen 431 of the nest400, with the front face of the finger board 506 facing downward towardthe body clamp 480 and with the neck heel 504 proximate to the lowerneck platen 431. Once the guitar neck 502 is in the proper position, theuser may secure the neck 502 in place by sliding the upper neck clamp438 and the lower neck clamp 440 downward to contact the surface of theneck 502. In some aspects, by manually adjusting either or both of theupper neck clamp adjustment knob 436 or the lower neck clamp adjustmentknob 435, the user adjusts the movement or pressure of the upper neckclamp 438 or the lower neck clamp 440, respectively. Optionally, in someaspects, the user may lock the clamps 438 and 440 in place.

The user may position a guitar body 510 onto the body platen 470 of thenest 400. The user may move the neck joint locator 460 downward, andinsert the joint locator pin 462 into the neck joint locator pin hole516 located on the front face 512 and near to the shoulder 514 of thebody 510. Optionally, the user may insert the bottom pin locator 466into the bottom pin hole 522 of the guitar body 510. Once the guitarbody 510 is in the proper position, the user may activate the vacuumsource 484 a-f by turning the T-handle 452 into the “on” position, tocreate a vacuum through each of the vacuum grips 482 a-g, which willcreate suction between the front face 512 of the guitar body 510 and thebottom surface 481 of the body clamp 480, thereby securing the body 510in place. With the guitar body 510 secured in place via the vacuum, theuser may remove the joint locator pin 462 from the neck joint locatorpin hole 516 by lifting the neck joint locator 460 upward, and away fromthe shoulder 514 of the body 510, particularly so that the neck jointlocator 460 does not interfere with the measuring and cutting tools thatwill contact the neck 502 and body 510.

With the guitar body 510 and guitar neck 502 secured in place, the usermay activate the system 10. With the specific aspects controlled, inpart, by the operational logic of the PLC 30, the probe 180 may measurethe dimensions, plane, angles, contours, geometry, surface features, andother features of the guitar neck 502 and guitar body 510, and the faceprobe 454 may measure the dimensions, plane, angles, contours, geometry,surface features, and other features of the front face 512 of the body510. Thus, for example, the PLC 30 may cause the probe actuator 194 tomove the probe 180 or probe shuttle 192 forward and backward along az-plane along the probe track 190, and may cause the probe planeactuator 198 to move the probe 180 in any necessary direction to allowthe sensor tip 186 to measure aspects of the neck 502 and body 510. ThePLC 30 may further cause the face probe actuator to move the face probe454 to allow the face probe sensor tip 455 to measure aspects of thefront face 512 of the body 510, particularly in the bridge locus area.

In some aspects, the system 10 measures the portion of the front face512 of the body 510 where a bridge will be mounted, for example, usingthe face probe 454. As shown in FIG. 15 a, and in view of the logicdiagrams of FIG. 16 and FIG. 18, the face probe tip 455 contacts thefront face 512 of the guitar body 510 (FIG. 15 a, part (A)), anddetermines if the bridge locus on the front face 512 is flat, concave,or convex, and communicates such information to the face probe processor458, which communicates the information to the PLC 30, where theinformation is stored and processed until routing of the wood commences.As diagrammed in FIG. 18, if the bridge locus of the front face 512 isflat, the PLC 30 may not calculate any adjustments in the shoulder angleon the guitar body 510. If the bridge locus of the front face 512 isconcave, the PLC 30 calculates the appropriate forward angle to be cutinto a shoulder portion 515 on the shoulder 514 of the body 510. If thebridge locus on the front face 512 is convex, the PLC 30 calculates theappropriate backward angle to be cut into the shoulder portion 515 ofthe shoulder 514 of the body 510. The calculations are temporarilystored in the memory of the PLC 30, and used to determine thepositioning of the body 510 and the first 120, second 130, and third 140routers during the cutting of the shoulder 514.

To ensure proper fitting together of the neck 502 and the guitar 510,the system 10 measures the angle between the heel 504 and the fingerboard 506, for example, using the probe 180. See FIG. 15 d, part (B). Asshown in FIG. 15 d, and in view of the logic diagrams of FIG. 16 andFIG. 19, the sensor tip 186 of the probe 180 contacts each of the bottomplane of the heel 504 and the back face of the finger board 506, anddetermines the angle at the junction between each piece, termed the neckangle, and communicates such information to the probe processor 184,which communicates the information to the PLC 30, where the informationis temporarily stored and processed until routing of the wood commences.If the neck angle is greater than a threshold angle, the PLC 30calculates the appropriate forward cut angle to be cut into the shoulderon the body 510. As diagrammed in FIG. 19, if the neck angle is equal toa threshold angle, the PLC 30 may not calculate any adjustments in theangle to be cut into the shoulder portion 515 of the shoulder 514 of thebody 510. If the neck angle is less than a threshold angle, the PLC 30calculates the appropriate backward cut angle to be cut into theshoulder portion 515 of the shoulder 514 of the body 510. The thresholdangle may be about 88, about 89, about 90, about 91, or about 92degrees. Preferably, the threshold angle is about 89 degrees, and morepreferably is 89.37 degrees. The calculations are temporarily stored inthe memory of the PLC 30, and used to determine the positioning of thebody 510 and the first 120, second 130, and third 140 routers duringcutting of the shoulder 514.

To ensure a proper bridge height, the finger board 506 should be seatedproperly in the guitar body 510. In this regard, the system 10 measuresthe thickness of the finger board 506, for example, using the probe 180.As shown in FIG. 15 b (part (C), and in view of the logic diagrams ofFIG. 16 and FIG. 20, the sensor tip 186 of the probe 180 contacts eachplane of the bottom portion the finger board 506 and determines thethickness of the finger board 506, and communicates the thickness to theprobe processor 184, which communicates the thickness to the PLC 30,where the information is temporarily stored and processed until routingof the wood commences.

The appropriate thickness of the finger board 506 is pre-programmed intothe PLC 30, and may depend, for example, on the particular model ofguitar. The desired thickness is termed the Nominal thickness, and aspresented in FIG. 20, is termed Nominal A. Thus, the probe 180determines deviations from the Nominal thickness in terms of whether thefinger board 506 of the neck 502 being processed is greater than or lessthan the established value for the Nominal thickness, Nominal A. The PLC30 calculates the appropriate angle to be cut into the shoulder 514 ofthe guitar body 510 to allow the finger board 506 to be seated properlyin the body 510. If the finger board thickness is determined to begreater than Nominal A, the PLC 30 calculates the difference inthickness to be cut into the shoulder 514, for example, by creating aforward cut heel pocket angle in the shoulder 514. If the finger boardthickness is determined to be less than Nominal A, the PLC 30 calculatesthe difference in thickness to be cut into the shoulder 514, forexample, by creating a backward cut heel pocket angle. If the fingerboard thickness is equal to Nominal A, the PLC 30 may not calculate anydifference in thickness, such that the depth of the shoulder pocket neednot be adjusted. The calculations are temporarily stored in the memoryof the PLC 30, and used to determine the positioning of the first 120,second 130, and third 140 routers for cutting the shoulder 514.

The sensor tip 186 of the probe 180 also determines the dimensions(e.g., length and width) of the lower portion of the finger board 506that will be seated into the finger board pocket, such that the lengthand width dimensions (in addition to the depth) of a finger board pocketmay be cut into the front face 512 of the guitar body 510 (FIG. 15 a,part (E)). These dimensions are communicated to the probe processor 184,which communicates the dimensions to the PLC 30, which calculates theappropriate length and width to be cut into the front face 512 of theguitar body 510 to allow the finger board 506 to be seated properly inthe finger board pocket. The calculations are temporarily stored in thememory of the PLC 30, and used to determine the positioning of the first120, second 130, and third 140 routers for cutting a finger board pocketin the front face 512. In some aspects, the PLC 30 creates a digitalprofile for both the finger board 506 edge and the heel 504 edge into aplurality of points, and uses these points to calculate the requiredpath of one or more of the first router 120, second router 130, or thirdrouter 140.

The male portion 508 of the dovetail joint 508, 518 preferably alignsproperly with the female portion 518 of the dovetail joint 508, 518. Toensure that each portion 508 and 518 aligns and fits together properly,the system 10 measures the angle of the male portion 508 of the dovetailjoint relative to the plane of the front face of the guitar neck 502,for example, by using the probe 180. See FIG. 15 b and FIG. 15 c. Inview of the logic diagrams of FIG. 16 and FIG. 21, the sensor tip 186 ofthe probe 180 contacts the male portion 508 of the dovetail joint 508,518 and determines whether the male portion 508 is positioned on thebottom face of the heel 504 perpendicular or non-perpendicular to thefront (and rear) plane of the guitar neck 502. If the male portion 508is not perpendicular, the sensor tip 196 determines the angle ofnon-perpendicularity, and communicates that information to the probeprocessor 184, which communicates the information to the PLC 30, wherethe information is temporarily stored and processed until routing of thewood commences.

If the angle is perpendicular, the PLC 30 may not calculate anyadjustments in the dovetail angle to be cut into the heel pocket. If theangle is non-perpendicular (the angle of non-perpendicularity), and isoff-position to the left direction, the PLC 30 calculates theappropriate angle to be cut into the left side of the heel pocket. Ifthe angle is non-perpendicular (the angle of non-perpendicularity), andis off-position to the right direction, the PLC 30 calculates theappropriate angle to be cut into right side of the heel pocket. Thecalculations are temporarily stored in the memory of the PLC 30, andused to determine the positioning of the first 120, second 130, andthird 140 routers for cutting the heel pocket.

The system 10, for example, by using the sensor tip 186 of the probe180, also determines the dimensions (e.g., length and width) of the heelportion 504 of the neck 502 (FIG. 15 e, part (F) and FIG. 17) that willbe seated into a heel pocket, such that the length and width dimensions(in addition to the depth) of the heel pocket may be cut into theshoulder 514 of the guitar body 510. These dimensions are communicatedto the probe processor 184, which communicates the dimensions to the PLC30, which calculates the appropriate length and width to be cut into thetop of the guitar body 510 to allow the heel 504 to be seated properlyin the heel pocket. The calculations are temporarily stored in thememory of the PLC 30, and used to determine the positioning of the body510 and the first 120, second 130, and third 140 routers during routingof a heel pocket into the shoulder 514.

The top drop angle is also measured by the probe 180 to help ensure thatthe guitar neck 502 and guitar body 510 come together properly. Forexample, as shown in FIG. 15 a, part (G), and according to the logicdiagrams of FIG. 17 and FIG. 22, the sensor tip 186 of the probe 180contacts the top portion of the front face 512 and determines the topdrop angle, and communicates this information to the probe processor184, which communicates the top drop angle to the PLC 30, where theinformation is temporarily stored and processed until routing of thewood commences.

The appropriate top drop angle is pre-programmed into the PLC 30, andmay depend, for example, on the particular model of guitar. The desiredtop drop angle is termed the Nominal top drop angle and, as presented inFIG. 22, is termed Nominal B. In some aspects, Nominal B is about 0.4degrees. In some aspects, Nominal B is about 0.47 degrees. Thus, theprobe 180 determines deviations from the Nominal top drop angle in termsof whether the top drop angle of the guitar body 510 being processed isgreater than or less than the established value for the Nominal top dropangle, Nominal B. If the top drop angle on the guitar body 510 is equalto Nominal B, no adjustments may be made to the shoulder angle. If thetop drop angle on the guitar body 510 is less than Nominal B, the PLC 30calculates the appropriate backward angle to be cut into the shoulder514 of the guitar body 510. If the top drop angle is greater thanNominal B, the PLC 30 calculates the appropriate forward angle to be cutinto the shoulder 514 of the guitar body 510. The calculations aretemporarily stored in the memory of the PLC 30, and used to determinethe positioning of the guitar body 510 and the first 120, second 130,and third 140 routers during cutting of the shoulder 514.

An uneven shoulder surface 515 may introduce undesired imperfections inthe fit between the guitar neck 502 and the guitar body 510. Thus, thesystem 10 measures the shoulder surface 515 at the shoulder 514 of theguitar body, for example, using the probe 180. As recited in the logicdiagrams of FIG. 17 and FIG. 22, the sensor tip 186 of the probe 180contacts the shoulder surface 515, determines if there are any lowspots, and measures the depth of such low spots. The depth of the lowspot(s) is (are) communicated to the probe processor 184, whichcommunicates the dimensions to the PLC 30, which calculates theappropriate depth to be cut into the shoulder surface 515 on the guitarbody 510 to allow the heel 504 to mate snugly with the shoulder surfacewhen the guitar is assembled.

Any adjustments in the plane of the shoulder surface 515 are gearedtoward the lowest depth among any low spots identified. If no low spotsare detected, the PLC 30 may not calculate any adjustments to theshoulder surface 515. If a low spot is detected, the PLC 30 calculatesthe depth to cut from the shoulder surface 515. The calculations aretemporarily stored in the memory of the PLC 30, and used to determinethe positioning of the guitar body 510 and the first 120, second 130,and third 140 routers for cutting the shoulder 514.

Having measured appropriate aspects of the guitar neck 502 and guitarbody 510, the system 10 automatically commences cutting of portions ofthe guitar neck 502 and the guitar body 510. The PLC 30 causes the hoistactuator 206 to move the hoist 202 to raise or lower the probe androuter assembly 100 to the appropriate height of the guitar neck 502 andguitar body 510 positioned on the nest 400. The PLC 30 may induceactuation of the bottom clamp actuator 474 to move the bottom clamp 472such that the guitar body 510 positioned in the nest 400 over the top ofthe bottom clamp 472 is positioned at the proper angle, for example,Nominal B. The PLC 30 may then induce actuation of the first, second,and third 174 router actuator and the first, second, and third 178 hingeactuator to move the first 120, second 130, and third 140 routers,respectively, to cut portions of the guitar neck 502 and guitar body510. In one non-limiting embodiment, cutting of the guitar neck 502 andguitar body 510 may proceed according to the logic flow shown in FIG.24. The order of cutting steps may vary.

Actuation of the first router actuator moves the first shuttle 152 and,with it, the first router 120, outward along the first track 150 towardthe nest 400 having a guitar neck 502 and guitar body 510 secured inplace. Actuation of the first hinge actuator moves the first router 120to its position in a vertical plane such that the first cutting tool 126points downward, and the first cutting tool 126 cuts a finger boardpocket profile onto the front face 512 of the guitar body 510 and, ifnecessary, finely cuts the edges of the corners of the lower portion ofthe finger board 506 such that the edges of the finger board 506 and thefinger board pocket in-the-making align. The finger board pocket profiletakes into account the determined geometry and dimensions of the lowerportion of the finger board 506.

The PLC 30 may induce actuation of the nest actuator 478 to move thenest 400 such that the guitar body 510 in the nest 400 is positionedinto the calculated heel pocket angle. Once the body 510 is positionedat the proper angle, the first router 120 cuts a heel pocket profileonto the shoulder 514 of the guitar body 510 and, if necessary, finelycuts the edges of the corners of the heel 504 such that the edges of theheel 504 and the heel pocket in-the-making align. The heel pocketprofile takes into account the determined geometry and dimensions of theheel 504. Following the cutting of a heel pocket profile, the firstrouter 120 is moved back into its position in a horizontal plane via thefirst hinge actuator and the first router actuator moves the firstshuttle 152 and, with it, the first router 120 inward along the firsttrack 150 back toward the gantry 200. In addition, following the cuttingof a heel pocket profile, the guitar body 510 is re-positioned atNominal B.

The PLC 30 may next induce actuation of the second router actuator,which in turn moves the second shuttle 162 and, with it, the secondrouter 130 outward along the second track 160 toward the nest 400.Actuation of the second hinge actuator moves the second router 130 toits position in a vertical plane such that the second cutting tool 136points downward, and the second cutting tool 136 cuts a finger boardpocket on the front face 512 of the guitar body 510, taking into accountthe geometry and the thickness of the finger board 506. After the fingerboard pocket is cut, the body 510 is positioned at the calculated heelpocket angle, and the second router 130 is re-positioned and cuts a heelpocket between the heel pocket profile on the shoulder 514 of the guitarbody 510. Cutting of a heel pocket takes into account the shape of thebridge portion of the front face 512, the neck angle, top dropdeviation, the depth of any low spots on the shoulder 514, and the shapeof the heel 504.

The PLC 30 may induce actuation of the nest actuator 478 to move thenest 400 such that the guitar body 510 in the nest 400 is re-positionedat Nominal B. Once the body 510 is re-positioned at Nominal B, thesecond router 130 (via the second cutting tool 136) may then cut thefinger board pocket between the finger board pocket profile on the frontface 512 of the guitar body 510. The finger board pocket takes intoaccount the calculations of the depth of the finger board 506. Followingthe cutting of the finger board pocket, the second router 130 is movedback into its position in a horizontal plane via the second hingeactuator, and the second router actuator moves the second shuttle 162and, with it, the second router 130 inward along the second track 160back toward the gantry 200.

The PLC 30 may then induce actuation of the nest actuator 478 to movethe nest 400 such that the guitar body 510 in the nest 400 isre-positioned into the calculated heel pocket angle. The PLC 30 may nextinduce actuation of the third router actuator 174, which in turn movesthe third shuttle 172 and, with it, the third router 140 outward alongthe third track 170 toward the nest 400. Actuation of the third hingeactuator 178 moves the third router 140 to its position in a verticalplane such that the third cutting tool 146 points downward, and thethird cutting tool 146 cuts the female portion 518 of the dovetail joint508, 518 into the shoulder 514 of the guitar body 510. Following thecutting of the female dovetail joint 518, the third router 140 is movedback into its position in a horizontal plane via the third hingeactuator 178 and the third router actuator 174 moves the third shuttle172 and, with it, the third router 140 inward along the third track 170back toward the gantry 200.

The male portion of the dovetail joint 508 (FIG. 25 a and FIG. 25 c) ispreferably cut at about a 10 degree angle, and the female portion of thedovetail joint 518 (FIG. 25 b) is preferably cut at about an 8 degreeangle. It is also preferred that the male portion 508 and the femaleportion 518 of the dovetail joint 508, 518 is tapered such that atighter fit with the male portion 508 and, ultimately, a tighter fitbetween the guitar neck 502 and the guitar body 510 can be achieved(FIG. 25 c). The taper 517 on the male portion 508 and the femaleportion 518 of the dovetail joint 508, 518 is preferably about 0.028inches per side of the dovetail, for a total of about 0.056 inches(1.422 mm) of tapering. The taper 517 is preferably about 0.0265 inches(0.673 mm) to about 0.0295 inches (0.749 mm) per side, for a total ofabout 0.053 inches (1.346 mm) to about 0.059 inches (1.499 mm) in totaltapering. The taper 517 is cut into the female portion 518 by the thirdcutting tool 146 of the third router 140 during the routing of theshoulder 514 of the guitar body. Thus, the female portion 518 of thedovetail joint 508, 518 comprises about an 8 degree angle on each side,and comprises a taper 517 of about 0.0265 inches (0.673 mm) to about0.0295 inches (0.749 mm) per side.

In some preferred aspects, the male portion 508 is about 10 degrees,with about a 0.922 inches (25.197 mm) width at the widest end of thedovetail 508. The female portion 518 is about 8 degrees, with about a0.935 inch (23.749 mm) width at the widest opening. The depth of thefemale portion 518 is about 0.696 inches (17.678 mm) and of the maleportion 508 is about 0.559 inches (14.199 mm). This geometry providesthe ultimate tight fit because the wood is compressed in the dovetailjoint 508, 518 due to the different dimensions of the male portion 508and the female portion 518.

A dovetail joint 508, 518 comprising a female portion 518 having aboutan 8 degree angle on each side and a taper 517 of about 0.0265 inches toabout 0.0295 inches per side, and comprising a male portion 508 havingabout a 10 degree angle on each side and a taper 517 of about 0.0265inches (0.673 mm) to about 0.0295 inches (0.749 mm) per side, is thusprovided. The dovetail joint 508, 518 joins together a guitar neck 502and guitar body 510. A guitar body 510 comprising a shoulder 514 havinga female portion 518 of a dovetail joint 508, 518 having about an 8degree angle on each side and a taper 517 of about 0.0265 inches (0.673mm) to about 0.0295 inches (0.749 mm) per side is provided. A guitarhaving a dovetail joint 508, 518 comprising a female portion 518 havingabout an 8 degree angle on each side, a male portion 508 having about a10 degree angle on each side, and a taper 517 of about 0.0265 inches(0.673 mm) to about 0.0295 inches (0.749 mm) per side is provided.

Once the guitar neck 502 and guitar body 510, and their subparts, havebeen properly routed/cut, the process is complete. The neck 502 and body510 including the refined dovetail joint 508, 518 may be removed fromthe nest 400, and a new neck 502 and un-routed body 510 can bepositioned and secured in the nest 400, and the measurement and cuttingprocess can then be repeated. Although placement and positioning of theneck 502 and body 510 are largely carried out manually by a user of thesystem 10, the subsequent measurements and cutting preferably proceed inan automated manner.

The system 10 is preferably suitable for high throughput routing of aguitar neck 502 and guitar body 510. The measuring and cutting steps mayproceed over the course of about 5 minutes or less from start tocompletion, and more preferably in less than 4 minutes, and even morepreferably in less than 3 minutes.

In some aspects, the system 10 may accommodate at least two guitar necks502 a and 502 b, and at least two guitar bodies 510 a and 510 b at onetime. For example, as shown in FIG. 13 and FIG. 14, a user may positiona second neck 502 b and a second body 510 b in one half of a nest 400 bhaving two sets of nest components 400 a and 400 b arranged in a mirrorimage. As the second neck 502 b and second body 510 b are positioned bythe user, the probe and router assembly 100 may automatically measureand cut a first neck 502 a and a first body 510 a already placed andsecured in the nest 400 a. When the measuring of the first neck 502 aand cutting of the first body 510 a are complete, the probe and routerassembly 100 may move laterally along the upper 208 and lower 212 gantrytracks and automatically measure the second neck 502 b and cut thesecond body 510 b having been properly positioned and secured by theuser. While the measurements and cutting take place on the second neck502 b and body 510 b, the user may remove the completed first neck 502 aand body 510 a from the nest 400 a, and load a new neck 502 a and body510A into the nest 400 a. The constituents of each nest 400 a and 400 bare identical, just configured to the orientation of the nest 400 a and400 b.

The invention also features computer readable media. A computer readablemedium may comprise executable code for causing a programmable processorto cause the probe 180 to measure portions of the guitar neck 502,including the neck heel 504, the finger board 506 and the rough-cut maleportion 508 of the dovetail joint 508, 518, and to measure portions ofthe guitar body 510, including the front surface 512, the shoulder 514,and the female portion 518 of the dovetail joint. A computer readablemedium may comprise executable code for causing a programmable processorto cause the face probe 454 to measure portions of the front face 512 ofthe guitar body 510. A computer readable medium may comprise executablecode for causing a programmable processor to cause the nest actuator 478to adjust the angle of the nest 400 and the guitar body 510 duringcutting. A computer readable medium may comprise executable code forcausing a programmable processor to calculate aspects of the geometryand surface features of the neck 502 and body 510, including whether thefront face 512 is flat, concave, or convex, neck angle deviations from athreshold angle, finger board 506 thickness, angle of perpendicularityor angle of non-perpendicularity of the male portion 508 of the dovetailjoint 508, 518 to the finger board 506, the dimensions of the fingerboard 506 and heel 504, the top drop angle, and horizontal position ofthe shoulder, among others. A computer readable medium may compriseexecutable code for causing a programmable processor to cause the firstrouter 120, the second router 130, and the third router 140 to cut/routportions of the front face 512 and shoulder 514 of the guitar body 510in order to create a finely-cut female portion of a dovetail joint 508,518 according to the unique geometry, shapes, dimensions, angles,imperfections, and other surface features measured from a neck 502 andbody 510 set.

A computer readable medium may comprise executable code for causing aprogrammable processor to carry out an operational logic used inoperation of the system 10 that enables measurement of the neck 502,body 510, and front surface 512, calculation of dimensions of and/orneeded for the male portion 508 and female portion 518 of the dovetailjoint, and positioning and movement of the nest 400 and the body 510 andof each of the first router 120, second router 130, and third router 140for making cuts in the wood. A computer readable medium may compriseexecutable code for causing a programmable processor to carry out theoperational logic of FIGS. 15-24. The computer readable media maycomprise a processor, which may be a computer processor.

The invention provides methods for cutting a dovetail joint 508, 518 ona guitar neck 502 and guitar body 510. The methods are preferablycarried out using a system 10 as described or exemplified in thisspecification. The methods preferably create a dovetail joint 508, 518as described or exemplified in this specification. Thus, a dovetailjoint 508, 518 produced according to a method for cutting a dovetailjoint 508, 518 is within the scope of the invention. The dovetail joint508, 518 produced according to such a method may be comprised in aguitar body 510 or a guitar neck 502, and may be comprised in anassembled guitar. A guitar body 510 comprising a dovetail joint 508, 518produced according to the methods is provided. A guitar neck 502comprising a dovetail joint 508, 518 produced according to the methodsis provided. A guitar comprising a dovetail joint 508, 518 producedaccording to the methods is provided.

In general, the methods comprise the steps (carried out in any order) ofdetermining if the bridge locus on the front face of a guitar body 510is flat, concave, or convex, determining if the neck angle between theheel 504 and the finger board 506 of a guitar neck 502 deviates from athreshold angle, determining the thickness of the lower portion of thefinger board 506 of the guitar neck 502, determining whether the angleof a dovetail joint 508, 518 on the heel 504 is perpendicular ornon-perpendicular to the finger board 506 of the guitar neck 502,determining the geometry of the finger board 506 and the heel 504,determining the top drop angle on the guitar body 502, and determiningthe horizontal position of the shoulder 514 of the guitar body 510.

In some aspects, any one or a plurality, including all, of thedetermining steps may be carried out using a processor programmed tocarry out the determining step. Thus, for example, determining if thebridge locus on the front face of a guitar body 51 is flat, concave, orconvex may be carried out using a processor programmed to determine ifthe bridge locus is flat, concave, or convex. Determining if the neckangle between the heel 504 and the finger board 506 of a guitar neck 502deviates from a threshold angle may be carried out using a processorprogrammed to determine neck angle deviations from a threshold angle.Determining the thickness of the lower portion of the finger board 506of the guitar neck 502 may be carried out using a processor programmedto determine the thickness of the finger board 506 of the guitar neck502. Determining whether the angle of a dovetail joint 508, 518 on theheel 504 is perpendicular or non-perpendicular to the finger board 506of the guitar neck 502 may be carried out using a processor programmedto determine the perpendicularity or non-perpendicularity of an angle ofa dovetail joint 508, 518. Determining the geometry of the finger board506 and the heel 504 may be carried out using a processor programmed todetermine the geometry of the finger board 506 and heel 504. Determiningthe top drop angle on the guitar body 502 may be carried out using aprocessor programmed to determine the top drop angle. Determining thehorizontal position (including determining low spots) of the shoulder514 of the guitar body 510 may be carried out using a processorprogrammed to determine the horizontal position of the shoulder. Theprocessor may be a computer processor, and may be comprised within acomputer.

Following the determining steps, the methods may further comprisecutting a finger board pocket on the front face of the guitar bodytaking into account the geometry, and optionally the depth, of thefinger board, cutting a heel pocket on the shoulder of the guitar bodytaking into account the shape of the bridge portion, the neck angle, thetop drop angle, the presence of low spots on the shoulder, thefingerboard thickness, and the geometry of the heel, and, cutting adovetail joint in the shoulder of the guitar body taking into accountthe angle of the dovetail joint on the heel.

In some detailed aspects, the methods comprise cutting the heel pocketon the shoulder at a forward angle if the bridge locus is concave, orcutting the heel pocket at a backward angle if the bridge locus isconvex. In some detailed aspects, the methods comprise cutting the heelpocket on the shoulder at a forward angle if the neck angle is greaterthan the threshold angle, or cutting the heel pocket on the shoulder ata backward angle if the neck angle is less than the threshold angle. Insome detailed aspects, the methods comprise cutting the heel pocket onthe shoulder at a forward angle if the finger board thickness is greaterthan a nominal thickness, or cutting the heel pocket on the shoulder ata backward angle if the finger board thickness is less than a nominalthickness. In some detailed aspects, the methods comprise cutting theopposite side of the dovetail angle at ½ the distance ofnon-perpendicularity if the angle of the dovetail joint on the heel isnot perpendicular to the finger board of the guitar neck. In somedetailed aspects, the methods comprise cutting the heel pocket on theshoulder at a backward angle if the top drop angle is less than anominal angle, or cutting the heel pocket on the shoulder at a forwardangle if the top drop angle is greater than the nominal angle. In somedetailed aspects, the methods comprise cutting the shoulder of theguitar body equal to the depth of the lowest low spot.

A dovetail joint 508, 518 at the junction of a guitar neck 502 and aguitar body 510 produced according to the methods is also provided. Aguitar body 510 having a female portion 518 of a dovetail joint producedaccording to the methods is also provided.

Although illustrated and described above with reference to certainspecific embodiments and examples, the invention is nevertheless notintended to be limited to the details shown. Rather, variousmodifications may be made in the details within the scope and range ofequivalents of the claims and without departing from the spirit of theinvention. It is expressly intended, for example, that all rangesbroadly recited in this document include within their scope all narrowerranges which fall within the broader ranges.

We claim:
 1. A method for routing a dovetail joint on a guitar shoulder,comprising: (a) determining if the bridge locus on the front face of aguitar body is flat, concave, or convex; (b) determining if the neckangle between the heel and the finger board of a guitar neck deviatesfrom a threshold angle; (c) determining the thickness of the lowerportion of the finger board of the guitar neck; (d) determining whetherthe angle of a dovetail joint on the heel is perpendicular ornon-perpendicular to the finger board of the guitar neck; (e)determining the geometry of the finger board and the heel; (f)determining the top drop angle on the guitar body; (g) determining thehorizontal position of the shoulder of the guitar body; (h) cutting afinger board pocket on the front face of the guitar body taking intoaccount the geometry of the finger board; (i) cutting a heel pocket onthe shoulder of the guitar body taking into account the shape of thebridge portion, the neck angle, the top drop angle, the low spot depthon the shoulder, the finger board thickness, and the geometry of theheel; and, (j) cutting a dovetail joint in the shoulder of the guitarbody taking into account the angle of the dovetail joint on the heel. 2.The method of claim 1, wherein the method comprises cutting the heelpocket on the shoulder at a forward angle if the bridge locus isconcave, or cutting the heel pocket at a backward angle if the bridgelocus is convex.
 3. The method of claim 1, wherein the method comprisescutting the heel pocket on the shoulder at a forward angle if the neckangle is greater than the threshold angle, or cutting the heel pocket onthe shoulder at a backward angle if the neck angle is less than thethreshold angle.
 4. The method of claim 1, wherein the method comprisescutting the heel pocket on the shoulder at a forward angle if the fingerboard thickness is greater than a nominal thickness, or cutting the heelpocket on the shoulder at a backward angle if the finger board thicknessis less than a nominal thickness.
 5. The method of claim 1, wherein themethod comprises cutting the heel pocket on the shoulder at the angle ofnon-perpendicularity if the angle of the dovetail joint on the heel isnot perpendicular to the finger board of the guitar neck.
 6. The methodof claim 1, wherein the method comprises cutting the heel pocket on theshoulder at a backward angle if the top drop angle is less than anominal angle, or cutting the heel pocket on the shoulder at a forwardangle if the top drop angle is greater than the nominal angle.
 7. Themethod of claim 1, wherein the method further comprises cutting theshoulder of the guitar body equal to the depth of the lowest low spot.8. A dovetail joint, comprising a wood female portion having an angle ofabout 8 degrees and a taper of about 0.0265 inches to about 0.0295inches per side and a wood male portion having an angle of about 10degrees and a taper of about 0.0265 inches to about 0.0295 inches perside.
 9. The dovetail joint of claim 8, wherein the female portion has ataper of about 0.028 inches per side and the male portion has a taper ofabout 0.028 inches per side.
 10. A guitar comprising a joint between theguitar neck and the guitar body, wherein the joint comprises thedovetail joint of claim
 8. 11. A guitar comprising the dovetail joint ofclaim
 9. 12. The dovetail joint of claim 8, wherein the widest end ofthe male portion measures about 0.922 inches in width.
 13. The dovetailjoint of claim 8, wherein the widest opening of the female portionmeasures about 0.935 inches in width.
 14. The dovetail joint of claim 8,wherein the depth of the male portion measures about 0.559 inches indepth.
 15. The dovetail joint of claim 8, wherein the depth of thefemale portion measures about 0.696 inches in depth.
 16. A dovetailjoint, comprising a wood female portion having an angle of about 8degrees and a taper of about 0.028 inches per side, about 0.935 inchesin width at the widest opening, and about 0.696 inches in depth, and awood male portion having an angle of about 10 degrees and a taper ofabout 0.028 inches per side, about 0.922 inches in width at the widestend, and about 0.559 inches in depth.
 17. A guitar comprising a jointbetween the guitar neck and the guitar body, wherein the joint comprisesthe dovetail joint of claim 16.